Field
Exemplary embodiments relate to a display device. More particularly, exemplary embodiments relate to an adaptive black clipping circuit for enhancing display quality, a display device including the adaptive black clipping circuit, and an adaptive black clipping method.
Discussion of the Background
A liquid crystal display (LCD) device that uses a thin film transistor (TFT) as a switching element is widely used. The LCD device includes a first substrate including pixel or pixel units each having a respective, to-be-charged pixel electrode, a second substrate including a common electrode, and a liquid crystal layer disposed between the first and second substrates. If an electric field having a same direction or polarity is continuously applied to the liquid crystal layer, a desired characteristic of a liquid crystal may be degraded. In order to prevent the degradation of the characteristic of the liquid crystal, an inversion driving method may be used which repeatedly inverts a polarity of a data voltage applied across the liquid crystal by unit of frame, by unit of row or by unit of pixel, where the polarity is with respect to a common voltage applied to the common electrode.
For example, in case of a dot inversion method (DIM) in which the polarity of the data voltage is inverted repeatedly by unit of pixel (that is, pixel by pixel), the degradation of the characteristic of the liquid crystal may be prevented or reduced. However, the process of providing the inverted or not inverted data voltages to respective individual pixels may be complicated, signals on the data lines may be delayed as a result, and power consumption of the LCD device may be disadvantageously increased. To solve the above-mentioned problems, a column inversion method has been proposed in which the data voltages having polarities different from each other are applied to adjacent data lines. When employing the column inversion method, the polarity of data voltage applied to each respective data line is inverted in each successive frame so that the applying process of the data voltage may be simplified, and the delay time of the signals on the data lines may be decreased.
To obtain the DIM checkerboard effect while instead using the column inversion method, pixels in a single column are alternately connected to one of two data lines adjacent to the column of pixels. In addition, a precharge driving method may be used to compensate for a charging time that tends to become shortened according to increase of resolution. However, when the precharge driving method is used, the appropriate precharging voltage is sufficiently charged only onto some pixel electrodes but not onto other pixel electrodes (where precharging is based on a previous data voltage applied to nearby pixel electrodes), and a difference of effective precharging relative to desired luminance can develop as between two adjacent rows of pixels. Accordingly, a difference of actual luminance between two adjacent rows of pixels (as opposed to desired luminances) may be undesirably created due to the difference of effective or ineffective prechargings applied to those adjacent rows. Thus, a horizontal dark or bright streak line may appear to be displayed on a display panel as an undesirable artifact resulting from the precharging process so that displayed image appears to have defects.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the inventive concept, and, therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.